We all know about the psychopath’s enhanced killer instinct, their finely tuned vulnerability antennae. But it may surprise you to know that there are some situations in
which psychopaths are actually more adept at saving lives than they are at taking them.
So let me give you an example of what I mean by that, okay? Imagine you’ve got a train and it’s hurtling down a track. In its path, five people are trapped on the line and cannot escape.
Fortunately, you can flick a switch, which diverts the train down a fork in that track, away from those five people, but at a price. There is another person trapped down that fork and the train will kill them instead. Question: Should you flick the switch?
Now, most people have little trouble deciding what to do under those
circumstances; though, the thought of flicking the switch isn’t
exactly a nice one, the utilitarian choice as it were, killing just
the one person instead of the five represents the least worst option,
But now let me give you a variation. You’ve got a
train speeding out of control down a track and it’s gonna plow into
five people on the line. But this time you are standing behind a very
large stranger on a footbridge above that track. The only way
to save the people is to heave the stranger over. He will fall to a
certain death, but his considerable bulk will block the train, saving
five lives. Question. Should you flick the switch?
Now we’ve got what we might call a real dilemma on our
hands, okay. While the score in lives is precisely the same as in the
first scenario, five to one, one’s choice of action appears far
trickier. Now why should that be? Well, the reason it turns out, all
boils down to temperature, okay?
Case one represents what we might call an impersonal
dilemma. It involved those areas of the brain, the prefrontal cortex,
the posterior parietal cortex, in particular, the anterior para
singular cortex, the temporal pole and the superior temporal sulcus -
bit of neuroanatomy for you there - primarily responsible for what we
call cold empathy, for reasoning and rational thought.
Case two, on the other hand, represents what we might
call a personal dilemma. It involves the emotion center of the brain
known as the amygdala, the circuitry of hot empathy. What we might
call the feeling of feeling what another person is feeling.
Now, psychopaths, just like most normal members of the
population, have no trouble at all with case one. They flick the
switch and the train diverts accordingly. Killing just the one person
instead of the five. But, this is where the plot thickens. Quite
unlike normal members of the population, psychopaths also experience
little difficulty with case two.
Psychopaths, without a moment’s hesitation are perfectly
willing to chuck the fat guy over the rails, if that’s what the doctor
orders. Now moreover, this difference in behavior has a distinct
neural signature. The pattern of brain activation in both normal
people and psychopaths is identical on the presentation of the
impersonal moral dilemma, but radically different when things start to
get a bit more personal.
Imagine that I were to hook you up to a brain scanner, a
functional magnetic resonance imaging machine, and were to present
you with those two dilemmas, okay. What would I observe as you went about
trying to solve them? Well, at the precise moment that the nature of
the dilemma switches from impersonal to personal, I would see the
emotion center of your brain, your amygdala and related brain
circuits, the medial orbital frontal cortex for example, light up like
a pinball machine. I would witness the moment in other words when
emotion puts it money in the slot.
But in psychopaths, I would see precisely nothing. And
the passage from impersonal to personal would slip by unnoticed.
Because that emotion neighborhood of their brains, that emotional zip
code has a neural curfew. And that’s why they’re perfectly happy to
chuck that fat guy over the side without even batting an eye.
Directed / Produced by
Jonathan Fowler & Elizabeth Rodd
More from the Big Idea for Wednesday, January 16 2013